| Channel ID | The unique ID of the current channel. |
| Channel Name | The name of the current channel. |
| Message ID | The unique ID of the current message. |
| Raw Data | The raw content of the destination connector message (equal to the encoded content of the source connector message). |
| Transformed Data | The serialized internal representation of the post-transformer message data. |
| Encoded Data | The state of the message data as it exists in the transformer. |
| Message Source | Depends on the inbound data type for the connector. For HL7 v2.x messages this will usually be the Sending Facility value in MSH.4.1. |
| Message Type | Depends on the inbound data type for the connector. For HL7 v2.x messages this will usually be the Type and Trigger values in MSH.9.1 and MSH.9.2. |
| Message Version | Depends on the inbound data type for the connector. For HL7 v2.x messages this will usually be the Version value in MSH.12.1. |
| Message Hash | The SHA-256 hash of the encoded data of the destination connector message. If no encoded data exists, the raw content is hashed instead. |
| Date | The current date and time, printed using a standard format. |
| Formatted Date | The current date and time, printed using a custom user-specified format. |
| Timestamp | The current epoch time represented in milliseconds. |
| Unique ID | An auto-generated universally unique identifier string. |
| Original File Name | Only applicable when the source connector is a File Reader. The name of the file currently being processed. |
| Count | A number that automatically starts at 1 when the channel is deployed, and increments for each message, or for each time ${COUNT} is used. |
| XML Entity Encoder | Automatically encodes any special XML characters (like "&;") into entities (like "&"). Useful when your message template is XML and you want to inject a custom variable into the inner text of a node. |
| XML Pretty Printer | Automatically indents and normalizes whitespace for the given XML string. |
| Escape JSON String | Automatically escapes any special JSON characters (like "{") with backslashes (like "\{"). Useful when your message template is JSON and you want to inject a custom variable into a string property. |
| JSON Pretty Printer | Automatically indents and normalizes whitespace for the given JSON string. |
| CDATA Tag | Inserts a CDATA tag, inside which you can place custom data without having to encode entities. |
| DICOM Message Raw Data | A special replacement token telling the destination connector to merge the destination connector message with any DICOM pixel data attachments and dispatch the fully merged bytes to the outbound endpoint. Typically used by the DICOM Sender destination. |
